While the above-described electronic devices have been diversified from a functional perspective, an advantage in portability will make the electronic devices more competitive. For example, even if electronic devices have the same function, an electronic device that is somewhat slimmer and smaller in weight and size, may be preferred. Accordingly, in practice, electronic device manufacturers put in effort to develop electronic devices that are slimmer and smaller in weight and size as compared with the other products while being equal or somewhat superior to the other products in functions.
As a part of the trend, the electronic devices include, in the inside thereof, removable external components, which have been selectively or essentially applied thereto, and such external components are being gradually miniaturized.
For example, such external components include card-type external components, such as a memory card, which may increase the storage space of an electronic device, and a Subscriber Identification Module so-called “SIM card,” which is removably mounted so as to allow two or more users, who have obtained different certifications, to use one electronic device. Efforts have been made in order to apply the external components to the electronic devices more efficiently.